Disaster in Paradise? Even the Sweetest Dreams Can Become Nightmares without Adequate Information and Preparation, Part 3 of 3

Leo and Sharon Wrobel conclude their three-part series with an example of the sort of helpful information available to businesses that are interested in relocating to exotic locations. (Or any location, for that matter.) Organizations like the Pacific Disaster Center can provide the details to help you make the right decision.

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The first two parts of this series presented some insights from the
Pacific Disaster Center
and the unique perspective of this quasi-government organization on disaster
recovery planning. We’ve saved the best for last! Before taking the plunge
and moving your business to some idyllic location (see Figure 1), how would you
like to be able to compute the precise probability of a disaster there? Using
information and tools provided by the PDC, it’s possible to make
extraordinarily accurate estimates of the probability of disaster. And a lot of
this information is free. Since you probably don’t have the
server capacity to store the literally terabytes of data you’ll need to
make a rational judgment (demographic, seismic, weather, topographic, oceanic,
and more), organizations like this can help you out by letting you look at their
data instead.

Figure 1 Gorgeous
rainbows in
Lahaina, on
the island of Maui in Hawaii, October 2007.

The PDC has developed the
Asia Pacific Natural Hazards and Vulnerabilities Atlas,
an extraordinary repository of data that can be used to examine the populations
and infrastructure at risk due to natural hazards present in a given region. The
Atlas provides decision makers and contingency planners like you with a resource
for understanding the types, frequencies, and severities of hazards that may
threaten their communities. It can play an important role in raising awareness
of these hazards and their associated risks, and in helping policy makers,
humanitarian assistance organizations, the international development community,
and the public at large to develop potential mitigation strategies.

NOTE

Many thanks to Ted Sheppard and Chris Chiesa from the Pacific Disaster Center
for their insightful contributions to this series of articles.

Southeast Asia Multi-Hazard Case Study

To show you the value of the available data for making decisions, we present
a case study that illustrates how the PDC’s Atlas can be used to examine
the combined risk posed by tropical cyclones and earthquakes in Southeast
Asia.

Step 1: Look for Natural Hazards

We begin by examining the potential for natural hazards that can cause harm
to a society’s people, infrastructure, or environment. Historical records
of these events can be examined using the PDC’s Atlas. Figure 2 shows the
locations and intensity of recent major earthquakes [1] in the Southeast Asia
region. The earthquake intensity layer underlying this diagram maps (with a 20%
probability) the Modified Mercalli intensity [2] expected to be exceeded during
a 50-year period for a given location. (The 50-year period represents the
average design life of a building.) For example, in Figure 2 the dark green
areas correspond to intensity expectations of V and below, while orange areas
have a 20% probability of experiencing an earthquake intensity of IX or higher
over the next 50 years. In the most seismically active areas, the symbols
representing epicenter locations almost completely obscure the underlying
intensity layer at this scale.

Figure 2 Earthquake
epicenters clearly outline the "Ring of Fire" along tectonic plate
boundaries. The background colors correspond to earthquake intensity zones and
are derived from the earthquake epicenter data.

The Zoom tools of the Atlas can be used to examine the data at a higher
resolution. The Identify and Select tools can be used to view details, including
magnitude and date, of recent or historical earthquake events.

TIP

The Help function of the Atlas provides details on the usage of these and
other tools.

Tropical cyclones can be investigated in much the same way. Figure 3 shows
tropical cyclone intensity zones for the same region we’ve just discussed.
The data maps areas that have a 10% probability of experiencing a tropical storm
of a given intensity during a 10-year period. Darker shades of blue correspond
to higher storm intensities. For example, light blue bands show areas that are
expected to experience a tropical storm with maximum sustained winds of 118 to
153 km/hr, while the darkest blue areas could expect a tropical storm with
maximum sustained winds over 250 km/hr.

Figure 3 Tropical
storm intensity zones estimate the most severe storm that a region is expected
to experience during a 10-year period based on analysis of historical storm
data. Tropical storm Inigo, active at the time this graphic was captured (April
2003), can be seen off the western coast of Australia.

Now let’s take this data and compare it to the critical infrastructure
located around our proposed business. Using the PDC’s tools, the
relationship between these hazards and potentially impacted resources can be
observed by displaying the hazards along with population centers, roads,
railroads, and airports. Figure 4 shows the earthquake risks, along with
transportation infrastructure, for a portion of the Philippines including
Manila. Figure 5 shows tropical storm risks for the same area.

Figure 4 The frequency
and severity of earthquakes in and around Manila places much of the region in
the top two categories of earthquake intensity. Most of metropolitan Manila can
expect an earthquake of intensity VIII or higher once per 50-year period (with a
20% probability), while the remaining eastern region can expect earthquakes with
even higher intensity (IX) during the same timeframe.

Figure 5 By
analytically combining both the Earthquake Hazard Index and the Tropical Storm
Hazard Index into a Multi-Hazard Index, the patterns are made even more evident
and, more importantly, can be used to assess hazard exposure to various
categories of human and natural resources.

As Figure 4 shows, this area is frequented by tropical storms, and falls
within the top end of the storm intensity zones. By creating a virtual overlay
of earthquake and tropical storm risks (see Figure 6), it’s possible to
draw some conclusions about the potential natural hazards to human populations
(see Figure 7).

Figure 6 Some regions,
such as the western portion of Borneo, face relatively low risk; others, such as
the Philippines, face a high risk of both earthquakes and tropical storms.

Figure 7 Southeast
Asian countries have some of the highest population densities in the world.
Indonesia, for example, is the fourth most populous country (behind only China,
India, and the U.S.), but has less than one quarter of the land area of the
U.S.

Step 2: Analyze Potential Exposure to Hazards

The next step in the multi-hazard risk assessment process is to analyze the
varying degree of potential exposure of people and infrastructure to the hazards
present in a region. The Atlas contains data layers for both population density
and transportation infrastructure (roads, railroads, airports). By combining
population density (see Figure 8) with transportation infrastructure (see Figure
9), we can examine the relative magnitude (or density) of people and
infrastructure exposed to potential harm from future occurrences of earthquakes
and tropical storms.

Figure
9 Transportation and infrastructure—including roads, railroads, and
airports—are subject to exposure to natural hazards as well as key to a
region’s recovery following such an event. The PDC’s Atlas supports
assessment of the vulnerability of these critical assets to various hazards.
Here this data is superimposed over the population density data.

Step 3: Identify High Impact Potential

Finally, the categorized population density data, along with the
transportation infrastructure data, are combined analytically with the
multi-hazard index to identify those areas with a high potential for impact from
these natural hazards (see Figure 10).

Figure 10 Areas with a
high hazard index and a high number of people and infrastructure systems would
warrant the most attention from mitigation efforts, as well as be expected to
require significant resources during the response and recovery phases of a
natural disaster.